REGULATION OF CYP1A1 IN HUMAN EPITHELIAL CELLS

人类上皮细胞中 CYP1A1 的调节

• 批准号: 2769608
• 负责人: B LYNN ALLEN-HOFFMANN
• 金额: $ 18.48万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-30 至 2000-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2769608
• 关键词: carbopolycyclic compound; cell adhesion; cell differentiation; cytochrome P450; drug receptors; enzyme induction /repression; epithelium; gene expression; human subject; keratinocyte; laboratory mouse; skin; tissue /cell culture

APPLICANT'S ABSTRACT: The focus of this proposal is to examine the tissue-specific regulation of a cytochrome P450 family member, CYP1A1, in normal human skin. CYP1A1 is a polycyclic and halogenated aromatic hydrocarbon-inducible monooxygenase. Since more than half of all cancers arise in epithelia having direct contact with the environment, an understanding of the endogenous regulation and expression of CYP1A1 in these tissues is important. Little is known about the tissue-specific regulation of CYPlA1 in normal human stratified squamous epithelia. However, PAHs and HAHs-dependent regulation of CYP1A1 is mediated by a basic helix-loop-helix transcription factor complex containing the aryl hydrocarbon receptor (AhR) and its dimerization partner, AhR nuclear translocator protein (Arnt). The role that AhR and Arnt play in tissue-specific CYP1A1 regulation in skin in not well understood. Furthermore, it is unknown if commitment to differentiation is necessary for CYP1A1 expression in skin or what role, if any, CYP1A1, AhR, and Arnt play in the terminal differentiation program of keratinocytes, the major cell type of stratified squamous epithelia. We have recently found that expression of the CYPlAl gene and enzyme activity is rapidly induced by cellular signaling events initiated by suspension of cultured human keratinocytes in the absence of xenobiotics or other differentiation-inducing conditions, such as high levels of calcium and serum. We suspect that similar cellular signaling events contribute to the induction of CYP1A1 in stratified squamous epithelia in vivo. This novel mechanism of CYP1A1 induction should enhance our understanding of mammalian cytochrome P450 gene regulation in stratified squamous epithelia and potentially aid in the identification of endogenous inducers and substrates for CYP1A1. The results we have generated thus far have led us to hypothesize that changes in cell adhesion are important regulators of CYP1A1 in normal human stratified epithelia. The specific aims are: 1) Characterize the endogenous expression of CYP1A1 in human keratinocytes, and in AhR+/+ and AhR-/- mouse keratinocytes at different stages of differentiation in vitro and in situ., 2) Investigate the molecular mechanism of CYP1A1 induction in keratinocytes following loss of cell-cell and cell-substratum contact, and 3) Identify specific cell-cell or cell-substratum interaction that, when disrupted, cause rapid induction of keratinocyte CYP1A1 and investigate the role of the AhR/Arnt signaling in adhesion-mediated CYP1A1 induction using AhR-/- mouse keratinocytes.

申请人的摘要：该提议的重点是检查 细胞色素P450家族成员CYP1A1的组织特异性调节 正常的人皮。 CYP1A1是一种多环和卤代芳香族 碳氢化合物诱导的单加氧酶。 由于所有癌症中有一半以上 出现在与环境直接接触的上皮中 了解CYP1A1的内源性调节和表达 组织很重要。 关于正常的Cypla1的组织特异性调节知之甚少 人分层的鳞状上皮。 但是，pahs和hahs依赖 CYP1A1的调节是由基本的螺旋 - 环螺旋转录介导的 含有芳基碳氢化合物受体（AHR）及其的因子复合物 二聚化伴侣，AHR核转运蛋白（ARNT）。 角色 AHR和ARNT在组织特异性的CYP1A1调节中播放的皮肤不 理解。 此外，未知是否承诺 差异化对于皮肤中的CYP1A1表达或角色是必不可少的 任何CYP1A1，AHR和ARNT在终端分化程序中播放 角质形成细胞，这是分层鳞状上皮的主要细胞类型。 我们 最近发现胞质基因和酶活性的表达 通过悬浮液的细胞信号传导事件迅速诱导 培养的人角质形成细胞在没有异种生物或其他的情况下 分化诱导条件，例如高水平的钙和 血清。 我们怀疑类似的细胞信号事件有助于 在体内分层鳞状上皮中CYP1A1的诱导。 这本小说 CYP1A1诱导的机制应增强我们对哺乳动物的理解 分层鳞状上皮中的细胞色素P450基因调节和 有助于鉴定内源诱导剂和底物 对于CYP1A1。 到目前为止，我们产生的结果使我们达到了 假设细胞粘附的变化是CYP1A1的重要调节剂 在正常的人分层上皮。 具体目的是：1） 表征了人角质形成细胞中CYP1A1的内源性表达，并且 在AHR+/+和AHR - / - 鼠标角质形成细胞中的不同阶段 体外和原位分化。，2）研究分子 损失细胞细胞后，CYP1A1诱导的机理 和细胞肌触点，以及3）确定特定的细胞细胞或 细胞 - 丝状相互作用，当破坏时，会引起快速诱导 角质形成细胞CYP1A1并研究AHR/ARNT信号在 使用AHR - / - 小鼠角质形成细胞粘附介导的CYP1A1诱导。